Brake



July 31, 4923.

E, R.. EVANS BRAKE Patented July 31, 1923..

aiv star lEDWIN R. EVANS, DETROIT, MICHIGAN. L.

- BRAKE.

`Application filed December 16, 1922. Serial No. @7341. I

Toa7Z whom t may cof/zoem.'

Be it-known that I, EDWIN R. EVANS,

a citizen of thefUnited States of. America,

residing at Detroit, in the county of Wayne..

and State of Michigan, have invented cer# tain" new andl useful Improvements inv Brakes, of which the lfollowing is a. specication, reference being had therein to the accompanying drawings.

This invention relates to steering wheel brakes for motor vehicles.

Features of thel invention are the employment of a camarranved to act upon a complementary pair vof e:brake shoes, and-self adjusting to equalize .the forces which itvv exercises upon said shoes; utilization of the cainto restrain the shoes from lateral shifting; provision of means for accurately taking up wear between the shoes and drum; and springs acting upon the brake shoes to exercise an anti-rattle effect.

Figure 1 is a diametricalsectional view of a wheel equipped withA the improved brake, the mountingvof said wheel upon its axle being also disclosed;

Figure 2 is a sectional view on line 2 2 of Figure -1 showing primarily the mounting of the brake shoes; i y

Figure 3 is a. sectional view taken on a plane parallel to that,of Figure '2 on line 3-'3 of Figure 1 but looking toward the wheel;

Figure' 4 is a sectional detail on line 4--4 ofFigure 1 showing the adjustment means whereby compensation may be made for. wear upon the brake shoes;

Figure 5 is a section on line 5--5 of Figure 2 showing a provision for preventing v as to exerc1se a wedge action upon Athe comrattle of the brake shoes; Figure 6 is a cross-section on line 6- of Figure 1 showing the -engagement of an actuating cam with the brake shoes.

In these views the reference character 1 designates the front axle of a vehicle and 2 one of the wheels upon said axle. For steering purposes it is the general practice to swivel the steering wheels upon the axle. Thus the wheel 2 is journaled upon a spindle 3 having apair of integral spaced bearings 4-respectively above and below the spindle axis for receiving the end portions of a pin- 5 which establishes the desired swivel steering axis through engagement with a bearing 6 integral withthe axle, between 'shoe ends.

'tegr-al with the bearings 4. 7 is a brakli drum secured by bolts 7a or some' other suitable means to the interior fac'e of the wheel 2 in the usual concentric relation to said wheel, and 8 `designates a pair of com'- pleinentary brake, shoes arranged within said drum, one at each side'of the'vertical axis the`reof,and provided with the customary linings 8a for frictional engagement vwith the drum, said brake shoes together forming an annulus of aA substantially Tssh'aped cross section, as best seen in Figure 5. 9 is a two-part' cylindrical pivot member for the two brake shoes arranged between the lower ends thereof and engaging complementary semi-cylindrical seats 10 formed in said ends, the axis of said pivot member being parallel to that of the wheel. The adjoining faces of the pivot elements 9 are formed with opposite justing head 11, the bottoms of said grooves being divergently inclined in parallelism with the divergent edge faces of said head. 12 is a stud-bolt projecting from the smaller end of'the head 11 in coaxial alignment with thc'pivot'member 9, and preferably integral with said head. Said, pivot member is provided with a support 13 and is axially adjustable w'ith respect to lsaid support for the purpose of adjusting the brake shoes to take up wear. Thus'- the ystud-bolt I grooves. 10a lto embrace a wedge-shaped ad- 12 is extended freely through a bore 13'l in the support 18 and a nut 14 terminally engaging said bolt bears -upon said support. By tightening said nut against'the support, the bolt 12 and adjusting head 11 may be shifted axially of the pivot 9 so plementary parts of said pivot, .thus adjustingv the pivotal extremities of the brake shoesto increase their spaced relation. It is necessary te 'restrain the pivot member 9 and adjusting lhead 11 from such laccidental turning as might shift 4the latter lfrom its transverse relation to the brake This restraint is exercised by a key 14 carried by a cylindrical guide 14b formed integral with the head 11 and vbolt 12 between the same, said key engaging a spline way 14' in the member 13. For holding the nut 14 'positively in adjustment, a spring-.pressed ball detent 14d' is selectively engageable with any of an,

` @i reaeasea sleeve 14et integral with said nut.

annularvseries of depressions 14.e formed in The support 13 is rigidly mounted by rivets 15 upon an annular sheet metal plate. 16 secured by rivets 17 to the periphery of the plate 4a. Thus it is evident that said plate 16 and the Apivot support for the brake shoes are carried'by the swivellcd spindlesupporting `plate Il so as to maintain a constant relation' with the brake drum in` any position of steeringadjustment of the Wheel. .'Above vand below the 'axis 'of the Wheel, the two brake shoes 8 are connected by coiled springs 18 and are urgedtherebyV toward each other about .the pivot `9,.so' `as to normally clear the brake drum.-

' The means for applying'the brakes comy prises a cam 19 located Within a. vertically `cylindrical liner pocket 19a journaled in the (sipposed upper. extremities ofthe brake ces. Said cani is elongated between the opposed 'end faces of the brake shoes,'in an oblique relation to said faces, and is of square (or. other polygonal) cross section With yrespect to its longitudinal axis', the

cam extremities being' spherically rounded,

, Saidjcam 4is freelyl longitudinally slidablein and passing through a slot 22 in the plate 16.y

shown). lt is an important feature of the construction that the cam 19 is'centered in a head 2 0 occupying the pocket' 19a and ycarxried, preferably integrally, by a rock-shaft 2 transverse to the major axis ofthe cam 23 is a standard integral Withthe axle'l adjacent the brake drum and forming at itsV upper end a bearing 24 in which the rock-shaft 21 is journaled. Said rock-shaft isexte'nded` beyond lthe bearing 2a to carry an .arm 25 for engagement by a brake controlfro'd (not alignment Witlithe axis o f the pin .5 about which the wheel has itssteering movement.

. As a provision against rattling Lof] the brake shoes it is preferred to loosely engage each shoe, at a ',pointsubstantially midway between its ends, by a bolt 26 rigidly secured .to the plate 16, a pair of coiled springs 27 being mounted upon each of -sa-id bolts, onev at each side of the corresponding brake shoe, said springs being under a suflicient stress to resist vibration of the brake shoes. Y

lin the operation ofthe described invenf tion, normally the brake shoes are held clear of the brake drumbv the lsprings 181.. To

. apply the brakes the shaft 21 Vis rocked in-a direction topreduc'e. Obliquity ofthe cam 19 to theengaged end faces of the brake shoes,'

thereby forcing the'brake shoes apart to an extent proportionateto the angular actuation of said shaft. Since the cam .19 'is centered' in alignment with the axis of the pin 5, about Which the wheell has its steering movement, the operative'relation of the camto the brake shoes is not effected by' any 'steering adjustment to which the Wheel may be subjected. The spherical form of the erivtremities and the cylindrical shape of the pocket 19l together permit a free turning of the Wheel for steering purposes Without any obstruction arising from said cam. Engagement of the head 20 in thecylindrical pocket 19a of the brake shoes maintains the latter centered at their upper ends with respect to the `brake drum andl prevents lateral play of" said ends. Since the Work'aim established by the cam 19 is of quite short radius, as

y.compared to the power arm established at 25, it is evident that the mechanism is such as to secure a very powerful braking force.

Witliav comparatively slight manual effort. `Wlien braking of a vehicle is effected by application of a restraining force to a pluralwheels. lin case the linings of any of the brake shoes Wear unequally there is a rcsultant tendency to' unequalized response to vthe braking elfort. The Apresent invention vprovides for a very accurate adjustment of 'the brake lshoes to insure equalization of the Abraking forces applied to the several Wheels." Thus, by turningthe nut 14 the pivotal extremities of the brake shoes may be spaced apart to a-veryclosely regulable degree, the

i adjustment `being rigidly maintained by said nut. Since the brake shoes are more or less responsive to actuationof the cani 19, ac-

rll` he slidingl mounting ofthe cam 19in the head-'2O is of advanta e in that said cam is .ity of the vehicle Wheels it is highly desirable .to equalize theforce applied to the' severa-lV thusinade self-adjusting -to'eifect equalization of the thrust transmitted through said 'cani to the respective brake.shoes, when the Sl1a`ft21 is rocked.-

What' ll-olaim as 'in invention is v 1;..lln a. brake mec anism,- the combination with a 4vehicle Wheel',xand` a' brake dr'uni 'carried `'by said wheeh-of a .journal member for said whee'ha".mountingforsaid journal member adapting the: same for a steering movement' abouta s wiyel axis substantially transverse to thatfiof'lthe journal member, a

pair ofcoinplement'ary lbrake shoes co-acting interiorly with saiddrurn and pivoted at oneend, v'the otherl ends of said brake shoes being formed with substantially radial channels arcuate With respect to saidI swivel axis, a rock shaft'substantially transverse to said swivel aXis,'a cam'upon said shaft engaging said channelled ends of the brake shoes, said cam being centered insubstantial alignment vwith said swivel axis and being elongated transversely of saidshaft, thebrake-shoe en-y gaging faces ofthe .cam being curved to conmember adapting the same for a'- steeringA movement about a swivel axissubstantiallytransverse ,to that of the journal member, a pair of complementary brake shoes -interiorly -coacting with said drum, a pivotal mounting for corresponding extremities of Vsaid brake shoes, the other extremities of said shoes being formed with complementary substantially semi-cylindrical radial channels, a rock shaft substantially transverse to said swivel axis, a cam upon said shaft engaging in said channels of the brake shoes, said cam being centered in substantial alignment with said swivel axis'and being elongated transversely of said shaft the ends of said cam established by said axis .being spherically rounded, and'means forrocking said'cam upon an axis transverse to 1ts major axis.

a pair of complementary brake shoes pivoted within said drum at corresponding'extremities, the other extremities of said shoes being formed with complementary substantially semi-cylindrical channels transverse to the axis of the brake drum, and a cam en# gaging in said channels-for spreading said brake shoes, restraining the latter from lat,- eral play through itslocation in said chan-' nels. y i

4. In a brake' mechanism, the'combination' with a brake drum, of a pair of complementary brake shoes interiorly en ageable with said drum, a pivot mounting or said brake shoes, a two part'pivot member,- the arts thereof having opposing relatively inc ined channels, a wedge member engagin the channels of the pivot parts, and a shan carried by said wedge member slidably engaging said pivot mounting and held from rotation thereon, said shank having a threaded portion, and anut upon said threaded portion bearing upon said pivot mounting for axially shifting the wedge member to spread the pivot parts and the pivotal ends of the brakeshoes.

5. In a brake mechanism, the combination with a brake drum, of a pair of complementary brake shoes interiorly engageable with said drum, a two-part pivot vmember en? gaging between corresponding endsvof said shoes, a lflat wedge memberengagin'g 'between said pivot forming members, for said pivot members being carried by said wedge member, and means for adjusting said wedge member axially of the pivot to spread the parts of the latter' and the pivotal ends of 6. In a brake mechanism, a brake shoe having a pocket opening in anen'd face. thereof transverse to the axis of the brake shoe, and a cam for actuating said shoe restraining the shoe from lateral movement by engagement in said pocket. '7. In a brake'mechanism, a pair of brake shoes having adjoining ends jointly forming a pocketv with an vopening therein extending transverse to the axis'of the brake shoe, anda cam member acting upon said ends for actuating said shoes and restraining the shoes from lateral movement by engagementl in said pocket.

8. The combination with a Wheel -for motor vehicles and the like, of a steering pivot for said wheel substantially transverse to the axis of the wheel, braking members for re- Atarding the movement of said wheel about its axis, means for actuating said braking II1embers,-and means for equalizing the action of said braking members vpermitting the normal turning movement of said wheel about its steering pivot.'

9: 'The combination with a wheel formo- A tor vehicles and the like, of a steering pivot 3. In a brake mechanism, a brake drum,-

forlsaid wheel substantially transverse to the axis of the Wheel, braking members for retarding the movement of vsaid wheel about its axis,`means for actuating said braking members, and a common means for equalizing the action of 'said braking members and compensating for changes in the position of -axis of thewheel, braking members for re-' tardingthe movement of said wheel about its axis, means for actuating said braking members, and means. for equalizing the action of said braking members permitting the normal turning movement of said wheel bers having a liner interposed between the ends of the braking members and the equalizing nieans. l v

` 1l. The combination with a wheel for motor vehicles and the like, of asteering pivot for said wheel substantially transverse to the axis ofthe wheel, braking members for retarding the movement of said wheel about its axis, means for actuating said braking members, and means for equalizing the action of said braking members permitting the normal turning movement ol.'V said wheel about its steering pivot, said braking members having a combined liner'and retaining about its steering pivot, said braking memmeans for the equalizing means' interposed tor vehicles and the like, of a steering pivot 139 l() f -izing means, said liner having retainin flanges on its opposite ends.

- 13. In a brake mechanism, the combinafor said wheel substantially transverse to thel axis ofthe Wheel, Abraking members for re". tarding the movement of saidv Wheel about its axis, means foractuatingfsaidbraking members, and means for equalizing the aotion ofsaid braking members permitting thev normal turningv movement of said Wheel labout its steering pivot, said-braking memberszhaving a liner interposed between the ends of the braking members and the equal# tion with a brakedrum, of apairof complementary drum shoes .interiorly engageable with said drum, a two-part pivot member i y engaging between. corresponding ends of said shoes, a stationary support, a Wedge `member for longitudinally moving said Wedge to separate the pivotal ends of the shoes.

maaien The combination With a Wheel for motor vehicles andthe like, of a steering pivot for said Wheel substantially transverse to the I axis of the Wheel, braking members for retarding the movement of said Wheel' about its axis, ireansf'for-actuating" said braking members, andf an equaliziiigv member for equalizing ther action of s'ald braking meinbers, said equalizing member and steering ,pivot being i substantial alignment in the Vdii'erent positions of turning movement of the Wheelabout its steering pivot.

I5. The combination with a Wheel for motor vehicles and the like, of a steering pivot for said Wheel substantially transverse to the aXisof the Wheel, braking members for retarding the movement of saidevvheel about .its anis, means foraotuating saidbraking members, andmeans for equalizing the aetion of said braking members, said means comprising a cam 'slidably mounted and having its ends constructed to permit of movement dit the Wheel aboutits steering pivot. 

